This invention relates generally to electronic bridge circuitry and structures. More particularly, this invention relates to bridge circuit and structure suitable for use in discrete element electronic circuits as well as integrated circuitry including a plurality of active and passive devices.
Although electronic bridge circuits and structures have heretofore been provided, such circuits and structures generally require a plurality of voltage supplies to drive the bridge circuit, provide only a balanced output for a balanced bridge input, require additional amplifiers to provide a single ended output, and require additional temperature compensation circuitry for operation. Smith, U.S. Pat. No. 3,495,159 is representative of this type of circuit. The bridge circuit suffers from requiring a number of amplifiers, the voltage supplies must track each other, and the bridge output is non-linear if the impedance elements do not vary in the same percentage amount for applied stimulus such as physical displacement, stress or acceleration applied to the bridge arms. Thus, there is a need for a high performance bridge circuit and structure for use in electronic bridge structures such as transducers for providing a bridge output in response to stress, acceleration or physical displacement.